Has the Cleveland-Lloyd Dinosaur Quarry Mystery Been Solved?

One of the most prolific dinosaur fossil sites to be found anywhere in the world lies thirty miles to the south of the town of Price in Utah.  The site is close to the small community of Cleveland (Emery County) and some 15,000 dinosaur bones have been collected from this site to date.  The strata represent Upper Jurassic siltstone (Brushy Basin member of the Morrison Formation) and this location is the densest collection of Jurassic dinosaur fossils known to science.

Jurassic Dinosaur Fossils

Since the first excavations were carried out in the late 1920s, palaeontologists have been puzzled by the assemblage of vertebrate fossils they found.  Although, carnivorous dinosaurs were probably less common in the palaeoenvironment than the plant-eaters, at this site, the fossils of theropods (carnivores) outnumbers the fossils of herbivorous dinosaurs by almost three to one.  In addition, the most common dinosaur fossil material is Allosaurus, the bones of this large dinosaur are extremely numerous at least forty-six individuals (based on femur bone counts) are recorded.

A Mounted Skeleton of the Late Jurassic Carnivore Allosaurus

The Papo Allosaurus new colour scheme.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture (above) shows a Papo Allosaurus model.

To view the Papo model range: Papo Dinosaur and Prehistoric Animal Figures.

For nearly one hundred years, palaeontologists have puzzled over this unique fossil assemblage.  Why is this particular location so full of the bones of carnivorous dinosaurs?  Why are the vast majority of these bones from a single genus – Allosaurus?

A Pie Chart Showing the Proportion of Different Dinosaur Fossils from the Cleveland-Lloyd Quarry

A pie chart showing the proportion of dinosaur fossils by genus.

Picture credit: PeerJ with additional annotation by Everything Dinosaur

The pie chart above lists dinosaur fauna plus one turtle (Glyptops) and a crocodyliform (Goniopholis) from the Cleveland-Lloyd Dinosaur Quarry.  The bone symbol identifies meat-eating dinosaurs and the fir tree, plant-eating dinosaurs.  The fossils of Allosaurus dominate the bonebed.

Theories Explaining the Cleveland-Lloyd Dinosaur Quarry Bonebed

Several theories have been suggested as to what caused the build-up of dinosaur fossils at this location and why the majority of them represent one carnivorous genus.

• This was a predator trap.  A pond attracted dinosaurs to the site as it was a source of water in the dry season.  These animals got stuck in the mud and they died, this in turn attracted scavengers who also become stuck and perished.
• This site could mark a mass death assemblage of a lot of dinosaurs which died in a drought.
• Was the water source toxic and this poisoned a lot of dinosaurs?  The rotting corpses attracted scavengers and these too were poisoned.

Writing in the academic journal “PeerJ” a team of researchers have put forward a new theory to explain the unusual taphonomy (the process of fossilisation).  The use of modern data techniques suggests that the quarry represents a series of catastrophic events that occurred at the same place over time, rather than a single mass death assemblage.

A New Theory

The research team, which included lead author Joseph Peterson (University of Wisconsin-Oshkosh), conclude that the myriad of small bone fragments found at the site, were created during periods of drought as bones which were not buried were weathered and eroded away on the surface.  Dinosaur carcasses were washed into the site which represented a temporary (seasonal or ephemeral pond) during frequent flood events.  As the corpses decayed, they led to very high levels of minerals and organic material in the water (hypereutrophic conditions).  This discouraged scavenging (which explains the lack of gnaw marks and other evidence of scavenging by predators at the site).

As more flood events took place, so more corpses were washed into the area and the existing skeletons were re-deposited.  Hence the jumble of bones.  The hypereutrophic water created an environment in which fish, turtles and crocodiles could survive and carnivorous dinosaurs were dissuaded from eating the carcasses.  Only a handful of crocodyliform teeth have been found at the Cleveland-Lloyd site, along with some turtle shell fragments, whereas, elsewhere in the Morrison Formation, turtle and crocodyliform teeth are much more numerous.

Explaining the Unusual Bonebed at the Cleveland-Lloyd Quarry Site

Explaining how the Cleveland-Lloyd fossil site came into being.

Picture credit: PeerJ

The image above reflects the newly proposed theory as to how the Cleveland-Lloyd Dinosaur Quarry formed.

(A) A flood causes the carcasses of dinosaurs to be deposited in the quarry area.  High levels of organic matter decaying leads to hypereutrophy (an excess of minerals in the water source).  This discourages predators from scavenging and deters freshwater fauna such as fish, turtles and crocodile-like creatures.

(B) As water levels fall during the dry season, bones that were not buried during the flood stage remain exposed on the surface.

(C) In arid conditions the surface bones are subjected to weathering and erosion.

(D) A subsequent flood event leads to more carcasses being incorporated and the reworking of existing bones within the deposit.

The scientists conclude that this cycle was repeated until the deposit maintained a higher water table, producing the limestone layers above the bone-bearing silts and muds.

A Model of the Fearsome Late Jurassic Predator Allosaurus (A. fragilis)

The new for 2017 Schleich Allosaurus dinosaur model.

To view the Schleich dinosaur model range: Schleich Dinosaur and Prehistoric Animal Figures. 

The picture (above) shows a Schleich Allosaurus model, one of an extensive range of Schleich dinosaurs.

Visit the Everything Dinosaur website: Everything Dinosaur.

World’s First Named Dinosaur Reveals New Teeth

The fossils that led to the first scientific account of a dinosaur can still provide some surprises, even 193 years after the original paper describing them was published.  The first dinosaur to be scientifically described Megalosaurus (M. bucklandii), has stepped once more into the spotlight.  A team of researchers have discovered five new teeth within the lower jaw fossil of the world’s first named dinosaur.

Megalosaurus Fossils Used to Describe the First Dinosaur in 1824

The partial dentary for teeth associated with Megalosaurus bucklandii.  Picture credit: Everything Dinosaur.

Picture credit: Everything Dinosaur

The picture above shows the right dentary of Megalosaurus.  It is on display at the Oxford University Natural History Museum.

Using state-of-the-art computer tomography scanning technology and three-dimensional computer generated modelling software, the researchers from the Warwick Manufacturing Group (WMG), an academic department at the University of Warwick, in collaboration with scientists from the University of Oxford’s Museum of Natural History have been able to provide new insights about one of the most iconic fossils in the world.

One of the authors of the study, presented this week at the Institute of Electrical and Electronics Engineers (IEEE)’s conference in Italy, Professor Mark Williams stated:

“Being able to use state-of-the-art technology, normally reserved for aerospace and automotive engineering, to scan such a rare and iconic natural history specimen was a fantastic opportunity.  When I was growing up I was fascinated with dinosaurs and clearly remember seeing pictures of the Megalosaurus jaw in books that I read.  Having access to and scanning the real thing was an incredible experience.”

Famous Dinosaur Jawbone

In 1824, the Reverend William Buckland published a description of various fossils that had been found as quarrying tunnels were excavated at Stonesfield, north of Witney in Oxfordshire.  The fossils had been found some years before, the dentary having been placed in the collection of the Oxford Anatomy School at Christchurch College (Oxford) in 1797.  Reverend Buckland believed the fossilised bones and teeth came from a giant, antediluvian lizard, hence the name “Big Lizard”, Megalosaurus having been proposed by James Parkinson in 1822.

A 19th Century Interpretation of Megalosaurus Compared to a Modern Interpretation of M. bucklandii

A modern interpretation of Megalosaurus (left) with a reconstruction based on the original illustration by Richard Owen (right).

Picture credit: University of Warwick/Mark Garlick

The illustration above shows an artist’s impression of how Victorian palaeontologists such as Richard Owen thought the Megalosaurus looked (right), compared with a modern interpretation of this Middle Jurassic carnivore.

Digital Three-dimensional Image of the Dentary

Using state of the art CT scanning technology and specialist three-dimensional analysis software, Professor Williams took more than 3,000 X-ray images of the world-famous Megalosaurus jawbone, creating a digital three-dimensional computer generated image.  The image revealed five previously unseen teeth embedded in the dentary and also provided important insights into historical repairs.  It turns out that there is actually less plaster and filler in the fossil, as this technique has allowed scientists to see the extent of the infilling and repairs for the first time.

Megalosaurus bucklandii was Probably an Apex Predator

The new for 2021 CollectA Megalosaurus in ambush dinosaur model.

The picture (above) shows the CollectA Megalosaurus in ambush dinosaur figure.

To view this range: CollectA Age of Dinosaurs Popular Figures.

Megalosaurus Fossil Jawbone

The specimen is damaged, it is likely that some of the damage occurred when the fossil was excavated but over the two hundred years since the fossil was found some restoration work has taken place.  For example, records at the Oxford University Museum of Natural History, where the specimen is housed, show that sometime between 1927 and 1931 repairs to the jawbone took place.  The scans show the true extent of repairs on the fossil for the first time, revealing that there may have been at least two phases of repair, using different types of plaster.  This new information will help the museum make important decisions about any future restoration work on this iconic fossil.

The analysis also revealed the presence of five teeth that had not been detected before.  The teeth consist of the remains of old, worn and broken teeth plus embryonic replacement teeth.  Unlike us, Megalosaurus was able to continually replace its teeth throughout its life.  The replacement tooth grew inside the jaw, adjacent to the root of the active tooth on the lingual* side of the jaw.

A full-sized, but very thin crown formed first and this grew in thickness as more layers of dentine were added.  The growth of the embryonic tooth placed pressure on the active tooth root, causing the root to become slowly reabsorbed into the jawbone.  The replacement tooth was able to push itself inside the old tooth root and effectively usurp that tooth from the socket in the jaw where it had been located.  The old, worn tooth having been weakened, would most likely break and the crown would be lost, permitting the younger tooth to replace it in the jawline.  A similar process is seen in extant Crocodylia today.

Helping to Identify Forgeries

This research was made possible through a collaboration between Professor Williams’ research group at WMG, University of Warwick – including PhD researcher Paul Wilson – and Professor Paul Smith, director of the Oxford University Museum of Natural History.   When not being scanned or used in other research, the Megalosaurus jawbone forms part of an extensive British dinosaur fossil display at the Oxford University Museum of Natural History.

An ability to utilise a non-invasive technique to map fossil material provides palaeontologists and conservators with vital information about the preservation status of a specimen.  It also identifies and maps any repairs that have taken place previously.  In addition, this technique which does not harm the fossil, can detect the presence of filler and other modifications often added by unscrupulous dealers to raise the potential value of their fossil finds.

Forgeries and hoaxes have no hiding place when it comes to CT scans.

The research was recently presented at the Institute of Electrical and Electronics Engineers (IEEE)’s International Instrumentation and Measurement Technology Conference in Torino, Italy.

The scientific paper, “Utilising X-Ray Computed Tomography for Heritage Conservation: The case of Megalosaurus bucklandii”

Visit the Everything Dinosaur website: Everything Dinosaur.

The Scaly Skin of Tyrannosauroids

So, it is published!  A team of eminent scientists, some of the leading lights in palaeontology, have published in the Royal Society Biology Letters details of research that questions whether Late Cretaceous tyrannosaurids, including the iconic Tyrannosaurus rex sported a coat of feathers.

Research into T. rex Feathers

At Everything Dinosaur, we have known about the fossils upon which this research is based, for some time.  Indeed, we are aware of a number of research projects taking place exploring the evidence for integumentary coverings in the Dinosauria.  This new study looks at skin impressions from several Late Cretaceous, giant tyrannosaurs and concludes that despite early tyrannosauroids having feathers, T. rex and its near relatives, most likely had scaly skin.

A Fluffy, Feather Covered Tyrannosaurus rex

The Dino Dana feathered T. rex video showcase titles.  A feathered T. rex.

Picture credit: Everything Dinosaur

The image (above) shows the Dino Dana feathered T. rex figure.

To view this range: Wild Safari Prehistoric World.

The research has generated some surprising headlines, looks like many media outlets have got into a bit of a flap:

“Feather furore: T. rex may not have been fluffy after all, skin study suggests” – The Guardian.

“Tyrannosaurus rex had scaly skin:  Here are the controversial reasons why scientists think the dinosaur was NOT covered in feathers” – Mail Online

“Jurassic Park may have been right about the T-rex after all” – Silicon Republic

“Here’s what it would feel like to pet a T. Rex” – National Geographic

Some quick points:

• If you publish a story that features Tyrannosaurus rex lots of media outlets are likely to cover it.
• You can expect some sensational headlines.
• Expect numerous faux pas when it comes to the “Tyrant Lizard King” – rapped knuckles for Silicon Republic and National Geographic!  No hyphen in T-rex, no capital letter for the trivial name etc.

What Does the Study Show?

The research team led by Dr Phil Bell (University of New England, New South Wales, Australia), examined the fossilised skin impressions associated with a partial skull and postcranial material of a Tyrannosaurus rex specimen “Wyrex” from the Hell Creek Formation of Montana.  These fossils are part of the vertebrate fossil collection at the Houston Museum of Natural Science, hence one of the co-authors, Robert T. Bakker’s (curator of palaeontology at the Houston museum), involvement in the study.

The specimen represents around 30% of an entire skeleton, it was excavated from upper Maastrichtian strata near the town of Baker (Montana), in 2003 and it was formerly part of the Black Hills Institute fossil collection (BHI 6230), hence the participation in the study by Pete Larson (Black Hills Institute of Geological Research, South Dakota).  The gracile form of the skeleton suggests that “Wyrex” was male.

Preserved Skin Impression on the Neck of “Wyrex”

Preserved integument from the neck (b) of T. rex specimen HMNS 2006.1743.01

Picture credit: Biology Letters

“Wyrex” is Special

“Wyrex” is special, as in association with the fossilised bones and teeth, several patches of the integument are preserved as impressions.  These impressions represent skin from the neck, the pelvic area and from the tail.  The tail skin impressions are the most numerous, but all of them combined do not represent a very large part of the surface area of a T. rex.  The patches are very small ranging in size from less than a postage stamp in area to an impression of approximately 30 square centimetres, a tail skin impression that that would have covered less than a third of the screen on an average mobile phone.  Although these impressions are very small, any form of integument preservation is remarkable and they have provided an invaluable insight.

Integument of Tyrannosaurus rex (HMNS 2006.1743.01)

The extent of the skin impressions on the “Wyrex” specimen.

Picture credit: Biology Letters

Skin Impressions on Tyrannosaurus rex Fossil

The picture above shows impressions and where they are located on the T. rex (see silhouette).  Three bones are shown (a), they are bones from near the base of the tail (caudal vertebrae 6-8) which are associated with skin impressions (f), (g) and (h).  Integument from the neck (b, c) and from the ilium (pelvis) in (d, e).  The line drawings show the great variation in the size and shape of the scales.  The researchers highlight the variety of the scales, some are elliptical, some are elongated, whilst others are irregular six-sided polygons.

Note the scale bars, in a lot of the media coverage, the actual size of the impressions has not been reported, the scale bars in the picture above:

(a) = 10 centimetres, (b-e) = 5 millimetres and (f-h) = 10 millimetres

Not Just Tyrannosaurus rex Skin in the Study

To the north of Montana, lies the Canadian Province of Alberta.  Geography lesson over, but noting the location of Montana is significant, as scientists from the University of Alberta and the Royal Tyrrell Museum (also in Alberta), have played a part in this research.  Illustrious figures from the world of palaeontology such as Professor Phil Currie and Scott Persons (University of Alberta) and Darren Tanke (Royal Tyrrell Museum).  These luminaries along with Nicolás Campione (Uppsala University, Sweden), have helped compile a new data set plotting tyrannosauroid integument against body size.

This study looked at fossil skin impressions from a number of other Late Cretaceous relatives of T. rex, monsters such as Albertosaurus, Gorgosaurus, Daspletosaurus, all from North America, plus Tarbosaurus from Asia.

The Late Cretaceous Daspletosaurus (Fossils found in Montana and Alberta)

The fearsome tyrannosaurid Daspletosaurus.

Picture credit: Everything Dinosaur

The model (above) is the CollectA Prehistoric Life Daspletosaurus.

To view this model range: CollectA Prehistoric Life Replicas.

Large-bodied Forms had Scaly Skin

The research team conclude that these large-bodied forms possesses scaly, reptilian-like skin.  By mapping integument against body size against the tyrannosauroids, a more extensive data set than just the Tyrannosauridae family, the team postulate that large body-size evolved two times in the evolutionary history of this substantial group.  Early tyrannosauroids such as Yutyrannus (Y. huali), which was feathered, was part of one branch of the tyrannosauroids that became giants and gigantism occurred again in later tyrannosaurids such as T. rex, Gorgosaurus, Albertosaurus et al.

The data suggests that shaggy, feathery coats as found in some early tyrannosauroids, were lost by the Albian faunal stage (around 112 million years ago).  Later tyrannosaurs, those that were the ancestors of the very last members of the Tyrannosauridae to evolve, did not have feathery coats.

 Yutyrannus Roamed Northern China 125 Million Years Ago

Giant theropod with Feathers from Liaoning Province

Picture credit: Brian Choo

To read an article about the discovery of Yutyrannus huali: One Tonne Feathered Tyrannosaur.

Yutyrannus – A Tyrannosaur Game Changer

The discovery of a large (up to nine metres long and weighing 1.4 Tonnes), tyrannosaur provided evidence that giant theropods could have been covered in a shaggy coat.  Prior to the description of Y. huali (the name means beautiful feathered tyrant), back in 2012, the only tyrannosaurs discovered with proto-feathers were much smaller animals, dinosaurs such as Dilong, (D. paradoxus), which also roamed China.  It had been thought that smaller tyrannosaurs, with their warm-blooded metabolisms evolved feathers to help keep their bodies insulated.  However, here was a much larger dinosaur, one that was also covered in feathers.

In this new research, the scientists conclude that the environment that Late Cretaceous giants such as Albertosaurus and T. rex lived in had a similar climate to the environment that Yutyrannus lived in millions of years before.  They discount the idea that the big Late Cretaceous tyrannosaurs had feathers to keep them warm.  The larger the animal, the smaller the surface area compared to their volume and therefore big creatures tend to be better at retaining heat than smaller ones.  In the paper, it is argued that a big, thick coat of feathers may have been a real hindrance to a Tyrannosaurus rex, as its active lifestyle could have given it serious problems with over-heating.

A Close View of the Skin Impression over the Pelvic Area (Ilium) of T. rex

T. rex integumentary covering over the ilium.

Picture credit: Biology Letters

Tyrannosauroid versus Tyrannosauridae

The assessment of these scale impressions along with the analysis of tyrannosauroid integument against body size does not necessarily mean that T. rex was definitely covered in scaly skin.  This new research may cast doubt on the idea of an adult, Late Cretaceous tyrannosaur looking like a giant chicken, but it is important to note that the researchers comment that dinosaurs such as Albertosaurus, Gorgosaurus and T. rex may have had feathers on those parts of the their body which are not represented by skin impressions in the fossil record – on their backs, or around the top of the head for example, hence the partially feathered Tyrannosaurus rex image featured in this article.

As juveniles, having an insulating covering of downy feathers does make anatomical sense.  The idea that members of the Tyrannosauridae may have had feathers at some stage of their lives cannot be discounted in the same way as that stating that T. rex may have had feathers on some parts of the body cannot be discounted as we lack the fossil evidence to disprove this statement.

The scientists do state that whilst more basal members of the Tyrannosauroidea may have had feathers, later more derived tyrannosaurs, those animals within the family Tyrannosauridae probably did not.   The key word to note is “probably”.

Let’s quickly explain what this means.

An Ancient Lineage of Dinosaurs

The tyrannosaurs are a very ancient lineage of dinosaurs, they evolved in the Jurassic and persisted right up until the Cretaceous mass extinction event.  The clade Tyrannosauroidea represents the family Tyrannosauridae, to which Albertosaurus, Tarbosaurus, Gorgosaurus, Daspletosaurus and T. rex are part, along with more basal, earlier tyrannosaurs.

Tyrannosauroids and Tyrannosauridae Explained

The difference between the Tyrannosauroidea and the Tyrannosauridae.

Picture credit: Everything Dinosaur

In the simplified diagram above, the Tyrannosauridae family is shown as being a part of the larger Tyrannosauroidea clade.  Some well-known examples of the Tyrannosauroidea clade as well as members of the Tyrannosauridae family are listed.

The Preservation Factor

Only in very exceptional circumstances can delicate feathers and proto-feathers be preserved.  Tough skin has a better preservation potential than filamentous feathers that formed a shaggy coat.  Feathers could have been present in members of the Tyrannosauridae, but they simply have not been preserved, so we have no evidence of their existence. Experiments revealing how the corpses of birds decay may help palaeontologists to better understand what happens to feathers after death and their likelihood of being preserved.

Conclusions

In what is a thought provoking and well-argued piece, the scientists comment that their findings reveal significant changes within the integument of tyrannosauroids, especially when compared to skin impressions of later members of the Tyrannosauridae.  These changes in body coverings require better understanding and further evidence to help palaeontologists to explain them.  The unambiguous loss of extensive body coverings in the Tyrannosauridae merits further discussion.

To mark the publication of the Biology Letters article, we cooked chicken.  We left the skin on and from the picture below, you can see the skin but there are no signs of the feathers that would have covered parts of the bird.  We suspect that this debate over the appearance of more derived tyrannosaurs is going to rumble on.

Commemorating the Publication with a Chicken Dish

Cooked chicken, you can see the skin but not much evidence of feathers.

Picture credit: Everything Dinosaur

Which Do You Prefer Feathered or Non-Feathered?

Which do you prefer a feathered or a non-feathered T. rex?

The scientific paper: “Tyrannosauroid Integument Reveals Conflicting Patterns of Gigantism and Feather Evolution”, by Phil R. Bell, Nicolás E. Campione, W. Scott Persons, Philip J. Currie, Peter L. Larson, Darren H. Tanke, Robert T. Bakker published in the Royal Society Biology Letters.

Visit the Everything Dinosaur website: Everything Dinosaur.

Sorting Out Eolambia caroljonesa

The Cedar Mountain Formation of the western United States has yielded a number of important dinosaur discoveries, helping to map the megafauna of America during the Cretaceous.  Iconic dinosaurs such as the armoured herbivore Gastonia and the “raptors” Deinonychus and Utahraptor are known from the various members that make up the Cedar Mountain Formation.  However, the most abundant dinosaurs in terms of the genera named are ornithopods and a team of scientists including researchers from the Field Museum (Chicago), have published a new paper helping to identify where, in the dinosaur family tree, one ornithopod – Eolambia caroljonesa should be placed.

An Ornithopod Dinosaur Riddle

The youngest member of the Cedar Mountain Formation (a member being a distinct, identifiable portion of a rock formation that can be identified as a stratigraphic unit), is the Mussentuchit Member and the most common dinosaur fossils associated with these strata relate to Eolambia caroljonesa.

This herbivorous dinosaur is known from quite extensive fossils including skull material and three bonebeds that contain the jumbled up remains of a number of juveniles.  Named by the famous American palaeontologist James Kirkland in 1998, Eolambia means “early or dawn Lambeosaur”, reflecting the proposed taxonomic position of this dinosaur as being a basal member of the lambeosaurines (crested duck-billed dinosaurs).

Eolambia caroljonesa

Over the last two decades, since the discovery and naming of Eolambia, many more iguanodontian dinosaurs have been named.  This has helped palaeontologists to better understand the evolution of ornithopods from the non-hadrosaurid forms known from the Early Cretaceous to the duck-billed dinosaurs which were prevalent during the Campanian to Maastrichtian faunal stages of the Cretaceous (Late Cretaceous).

Writing in the on-line academic journal PLOS One, the researchers describe some further postcranial remains of Eolambia from the Mussentuchit Member.  The fossils represent a sub-adult animal and as a result, these bones are more helpful when it comes to establishing autapomorphies (unique features), that help to establish where in the dinosaur family tree Eolambia should be nested.

The Eolambia Postcranial Fossils Laid Out in an Approximate Life Position

Eolambia postcranial fossil material laid out in approximate life position.

Picture credit: PLOS One with additional annotation by Everything Dinosaur

Calculating the Size of Eolambia caroljonesa

The picture above shows the newly described postcranial fossil material laid out in approximate skeletal position, using the better known iguanodontid Mantellisaurus atherfieldensis as a template.  The scale bar equals one metre.  One of the outcomes of this new study is that the research team will be able to provide a better estimate of the true size of Eolambia.

When first named by Kirkland, this dinosaur was estimated to be around eight to nine metres in length.

However, Gregory S. Paul (2010), suggested that Eolambia was considerably smaller with a total body length of around six metres.  Having to rely on juvenile material makes estimating the adult size of a dinosaur very difficult.  The ilium (number 26 in the picture above), measures a fraction under seventy-one centimetres in length.  Everything Dinosaur team members have examined their data files and compared this measurement to the size of ilia from other iguanodontids.  For example, the ilium of the Spanish iguanodontid Delapparentia turolensis measures seventy-eight centimetres long.  As Delapparentia is estimated to have been up to ten metres in length, it is likely that a fully-grown Eolambia could perhaps measure around nine metres from nose to tail.

Comparing Eolambia Pelvic Material (E. caroljonesa)

Eolambia pelvic material (sub-adult specimen compared to juvenile material).

Picture credit: PLOS One

The picture above shows the sub-adult pelvic material representing the new specimen FMNH PR 3847 (A, B, E, F, H and K) compared to other known fossil material including juvenile remains (C, D, G, I and J).  The scale bar equals ten centimetres.  Histological analysis from a sample of rib bone indicates that this dinosaur was between eight to nine years of age when it died.

Eolambia in the Dinosaur Family Tree

Specimen FMNH PR 3847 provides new anatomical detail regarding the back bone and pelvic girdle of E. caroljonesa.  As the fossils come from a sub-adult, the scientists have been more confident in the phylogenetic assessment of where within the Ornithopoda Eolambia should be nested.  The researchers conclude that this dinosaur was only very distantly related to the lambeosaurines and that it was a basal hadrosauromorph closely related to Protohadros byrdi, fossils of which come from similarly aged rocks (Cenomanian faunal stage), from Texas (Woodbine Formation).

An Illustration of Eolambia

An illustration of the hadrosauromorph Eolambia.

Signs of a Predatory Dinosaur

The fossils were deposited in strata that was formed in a crevasse splay feature – sediment deposited when a stream breaks its banks and deposits sediment on the flood plan.  Along with the dinosaur bones the scientists identified a large number of crocodylomorph teeth and small bones and a tooth from a gar (fish).  Intriguingly, the team also found broken teeth from a large, meat-eating dinosaur.  Although, the exact taxon cannot be pinned down, the scientists postulate that these teeth could have come from Siats meekerorum, an apex predator known from similar aged strata in Utah.

Teeth Found in Association with the Eolambia Material

Views of a tooth from a gar (fish) and below a theropod tooth Siats meekerorum?

Picture credit: PLOS One

The scale bar for the single gar tooth (several views) is 0.2 centimetres, the scale bar for the theropod tooth is 0.5 centimetres.

The Eolambia species name honours Carole Jones who, along with her husband Ramal Jones, discovered the fossil site from which the first fossils of this dinosaur including the holotype material was collected.

For dinosaur models and prehistoric animal replicas: Dinosaur and Prehistoric Animal Models.